Oiler apparatus for power tools

ABSTRACT

An oiler apparatus for power tools automatically supplies oil to the moving parts of the tool when the tool is actuated and may be manually operated to supply oil when desired. The oiler apparatus includes a plunger reciprocably mounted within a casing having inlet and outlet means for supplying oil to the casing and for conducting oil from the casing to the parts to be oiled. Linkage means extends from the plunger to adjacent the throttle trigger or other actuating means for operating the tool. The linkage means is engaged by the trigger when the trigger is pulled to operate the tool whereby the linkage and the plunger are moved to pump oil through the outlet means of the casing. A manual actuator which is also engageable with the linkage means is mounted adjacent the trigger, and the linkage and the plunger can be moved by the manual actuator independently of the trigger.

[451 Oct 9, 1973 United States Patent Gottlieb Primary Examiner-SamuelF. Coleman Assistant Examiner-H. Grant Skaggs, Jr.

[ OILER APPARATUS FOR POWER TOOLS [75] Inventor: Alfred Gottlieb, Crete,Ill.

[73] Assignee: DESA Industries, Inc., Cockeysville,

Attorney-Dawson, Tilton, Fallon & Lungmus [57] ABSTRACT An oilerapparatus for power tools automatically supplies oil to the moving partsof the tool when the tool is actuated and may be manually operated tosup- [22] Filed: Apr. 11, 1972 ply oil when desired. The oiler apparatusincludes a plunger reciprocably mounted within a casing having 211 Appl.No.: 242,981

and outlet means for supplying oil to the casing for conducting oil fromthe casing to the parts to be oiled. Linkage means extends from theplunger to adjacent the throttle trigger or other actuating means thetool. The linkage means is engaged when the trigger is pulled to operatethe tool whereby the linkage and the plunger are moved the outlet meansof the casing. A

manual actuator which is also engageable with the linkage means ismounted adjacent the trigger, and the linkage and the plunger can bemoved by the manual actuator independently of the trigger.

2,944,538 7/1960 Conway et al. 184/15 R 2,206,730 4/1939 Pihiquist et222/191 OILER APPARATUS FOR POWER TOOLS BACKGROUND This inventionrelates to an oiling apparatus for power tools. The apparatus findsparticular utility in chain saws and will be described in conjunctiontherewith, although it will be understood by those skilled in the artthat the oiling apparatus may be used with other power tools.

Chain saws conventionally include an endless saw chain which rides onthe guiding surfaces of an elongated guide bar and power means, such asan internal combustion engine, which is operatively connected to the sawchain, as by a sprocket wheel, to drive the saw chain around the guidebar at high speed. Because of the high speed movement of the saw chainover the guiding surfaces of the guide bar, it is important to providelubrication for the chain and the guide bar.

In the past lubrication has generally been provided by a manuallyoperated oiler which includes an oil pump having a manually operatedplunger. When lubrication was required, the plunger was manuallyoperated to pump oil to the guide bar to lubricate the guiding surfacesof the guide bar and the chain. However, operators of chain sawsfrequently forget or simply neglect to operate the oiler, or do notoperate the oiler often enough to provide sufficient lubrication underextreme working conditions. In any of these situations damage to thechain saw can result.

SUMMARY The invention provides an oiling apparatus which isautomatically operated whenever the throttle of the engine isoperated toincrease the speed of the saw chain and which can also be operatedmanually when desired to supply additional oil while maintaining fullthrottle operation or to supply oil when the engine is idling. Theoiling apparatus includes a pump having a reciprocable plunger andlinkage which extends from the plunger to a position adjacent thetrigger which operates the throttle. The end portion of the linkageextends parallelto the axis of rotation of the trigger, and when thetrigger is rotated to increase the speed of the saw chain, the triggerengages the linkage and moves the plunger to pump oil to the guidebarand chain. Amanually operable bell crank means is rotatably mountedadjacent the trigger and is connected to the end portion of the linkage.The bell crank can be rotated to move the linkage and the plungerindependently of the trigger when the saw chain is moving either atidling speed or at cutting speed.

DESCRIPTION OF THE DRAWING The invention will be explained inconjunction with an illustrative embodiment shown in the accompanyingdrawing, in which:

FIG. 1 is a perspective view of a chain saw equipped with the invention;

FIG. 2 is a fragmentary top sectional view of the chain saw withportions thereof omitted for purposes of clarity;

FIG. 3 is a fragmentary sectional view taken along the lines 33 of FIG.2;

FIGS. 4-8 are diagrammatic views illustrating the operation of theoiling apparatus. FIG. 4 illustrates the relationship between thethrottle trigger and the oiling apparatus when the chain saw is idling;FIG. 5 is a fragmentary top view of FIG. 4; FIG. 6 is a viewillustrating manual operation of the oiling apparatus when the engine isidling; FIG. 7 is a view illustrating automatic operation of the oilingapparatus; and FIG. 8 is a view illustrating manual operation of theoiling apparatus when the engine is operating at cutting speed.

DESCRIPTION OF SPECIFIC EMBODIMENT Referring now to FIG. 1, thenumeral10 designates generally a chain saw which includes a housing 11, a guidebar 12, and an endless saw chain 13 which is trained over the guide barfor movement along the guiding surfaces thereof. The housing includes aright hand or rear handle 14 and a left hand or forward handle 15. Thechain saw is conventional and need not be explained in detail.

The saw chain is driven by a sprocket wheel which is rotated by aninternal combustion engine (not shown) mounted within the housing 11.Alternatively, an elec tric motor could be used to drive the saw chain.Fuel is fed to the engine by a conventional carburetor 16 (shown insolid outline in FIG. 2 and in phantom in FIG. 3) which includes athrottle or shutter plate 17 and a crank 18 for rotating the shutterplate.

The shutter plate is controlled by a throttle trigger 19 which ispivotally or rotatably mounted within the housing by a pin 20. Thethrottle trigger includes a tinger portion 21 which extends from thehandle 14 and actuating portion 22 which extends upwardly from the pin20. The trigger is connected to the throttle crank 18 by conventionallinkage 23 which has a first end portion 24 which extends through anopening in the crank 18 and a second end portion 25 which extendsthrough an opening in the upper portion 22 of the trigger. The endportion 24 extends generally parallel to the axis of rotation of thecrank 18 and is rotatably received by the opening in the crank, and theend portion 25 extends generally parallel to the mounting pin 20 of thetrigger and is rotatably received by the opening in the trigger.

As can be seen best in FIG. 2, the rear end of the guide bar 12 issecured to the chain saw housing by means of a guide bar support pad 26and a bolt 27. An oil tank or reservoir 28 is formed within the forwardportion of the housing adjacent the rear end of the guide bar by side,bottom and rear walls 29, 30, and 31,.

and an oil pump 32 is mounted within the tank. The pump 32 includes anouter cylinder or casing 33 which is secured to the inside of thehousing and a plunger or piston 34 which is reciprocably received withinthe casing. A helical coil spring 35 is positioned in the casingforwardly of the plunger for biasing the plunger toward the rear of thechain saw.

Oil is supplied to the casing 33 by means of an oil inlet line 36 whichextends from the oil reservoir to the wall of the casing and whichincludes a check valve 37 which permits oil to flow into the casing butprevents outflow. An oil outlet line 38 communicates with the interiorof the casing 33 and extends through the guide bar support pad 27 to theguide bar. A check valve 39 is positioned in the oil outlet line forpermitting oil to flow from the casing to the guide bar but forpreventing backflow.

The plunger can be moved forwardly against the bias of the return spring36 by linkage 40 which extends through an opening in the end cap 41 ofthe casing. The

forward end of the linkage 40 is somewhat rounded and is received incorrespondingly shaped recess in the rear end of the plunger 34, and thelinkage extends rearwardly through the rear wall of the oil tank andalongside the carburetor 16. The linkage terminates in an end portion 41which extends generally parallel to the trigger pin and the end portionof the throttle linkage 23. If desired, the plunger linkage 40 can beprovided in two parts for ease of assembly which are joined by aconnector. The linkage passes through a suitable sealing member mountedin the rear wall 31 of the oil reservoir, such as rubber washer 42,which prevents oil leakage.

A pivot pin 43 is rotatably mounted in the rear handle portion of thehousing and extends outwardly from the left side of the handle andterminates in a flattened end portion 44. An oiler lever 45 providedwith a recess which is shaped to nonrotatably receive the end portion 44of the pivot pin is mounted on the end portion of the pin and extendsalongside the handle. A crank or lever 46 is non-rotatably mounted onthe pivot pin 43 within the housing, and the end portion 41 of the oilerlinkage extends through an opening in the crank 46.

The operation of the oiler apparatus will be explained with reference toFIGS. 4-8. FIG. 4 diagrammatically illustrates the throttle and oilerportions of the chain saw when the chain saw is in the idle position andthe saw chain is revolving around the guide bar relatively slowly. Theshutter plate 17 is in its idle position within the throat of thecarburetor 16, and the throttle crank 18 is connected to the shutterplate by pin 45 to cause rotation of the throttle plate as the crankrotates. The actuating portion 22 of the trigger 19 is spaced slightlyrearwardly of the end portion 41 of the oiler linkage, and the oil pumpplunger 34 is maintained in its rearward position by the return spring35 (not shown in FIG. 4). In this position, no oil is being pumped tothe guide bar.

If it is desired to lubricate the guide bar and the saw chain when thesaw chain is running at idle speed, the oiler lever 45 is depressed bythe thumb T of the right hand of the operator as indicated in FIG. 6.The lever 45 and the crank 46 are both fixed to the pivot 43 and therebyact as first and second lever portions of a bell crank, i.e., as thelever 45 is depressed, thecrank 46 rotates in the same direction to movethe oiler linkage 40 forwardly. Forward movement of the oiler linkagemoves the plunger 34 forwardly within the casing 33 and pumps oilthrough the oil outlet line 38 to the guide bar. Since the oiler leverand the oiler linkage is mounted independently of the throttle triggerand throttle linkage, the guide bar can be lubricated without changingthe position of the shutter plate of the carburetor.

When it is desired to use the chain saw for cutting, the speed of thesaw chain is increased by pulling the lower portion of the throttletrigger as shown in FIG. 7. The actuating portion 22 of the trigger isthereby caused to rotate forwardly or clockwise as viewed in FIG. 7 tomove the throttle linkage 23, the throttle crank 18 and the shutterplate 17 to increase the amount of fuel supplied to the engine. Forwardmovement of the actuating portion 22 of the trigger also brings theactuating portion into engagement with the end portion 41 of the oilerlinkage and pushes the oiler linkage forwardly to move the oil pumpplunger and pump oil to the guide bar. Forward movement of the oilerlinkage is permitted by rotation of the crank 46 and the oiler lever 45even though the oiler lever is not depressed. The guide bar and chainare therefore automatically lubricated each time the throttle trigger ispulled.

When the chain saw is being operated at cutting speed for a sustainedperiod of time, for example, when cutting through a relatively largelog, it may be desirable to lubricate the guide bar and the chainwithout decreasing the speed of the chain. The length of the casing 33of the oil pump is such that when the throttle trigger has been pulledto move the shutter plate to the full throttle position shown in FIG. 7,the plunger has been moved forwardly only to an intermediate positionwithin the casing. The plunger can therefore be moved forwardly anadditional distance to pump oil to the guide bar by manually depressingthe oiler lever 45 with the thumb to further rotate the bell crank meansand push the oiler linkage forwardly. Since the oiler lever is locatedalongside the handle 14, the oiler lever can be depressed with the thumbwhile the index finger maintains the trigger in the full throttleposition. When the oiler lever is released, the return spring returnsthe plunger and the oiler linkage to the position illustrated in FIG. 7,and the suction provided by the rearward movement of the plunger drawsoil into the casing from the oil reservoir through the check valve 37.The oiler can then again be operated manually to lubricate the guide barwhen desired without releasing the trigger.

When the trigger is released, conventional return means associated withthe trigger or the carburetor returns the trigger and the throttlelinkage to the position illustrated in FIG. 4, and the return spring 35returns the plunger and the oiler linkage to the position illustrated inFIG. 4. As the plunger is returned, oil is pulled into the casing fromthe oil reservoir.

From the foregoing it is seen that the oiler apparatus is operatedautomatically whenever the chain saw throttle is operated, and the guidebar and chain will be lubricated to prevent damage even if the operatorforgets or neglects to operate the oiler manually. The oiler apparatuscan be operated manually independently of the throttle when the chainsaw is being operated at either idle speed or cutting speed.

Although I have described a piston-type pump, it will be apparent thatother types of pumps can be used. The oiler linkage would then beoperatively connected to the movable pumping member. Further, theapparatus could be used with other power tools which have a moving workpart that requires lubrication such as a drill, bank saw, and the like.

While in the foregoing specification, a detailed description of aspecific embodiment of the invention was set forth for the purpose ofillustration, it is to be understood that many of the detailshereingiven may be varied considerably by those skilled in the artwithout departing fromthe spirit and scope of the invention.

I claim: a

1. In a chain saw having a housing, an elongated guide bar mounted onthe housing and extending therefrom, an endless saw chain trained aroundthe guide bar, power means within the housing for moving the saw chainaround the guide bar, and trigger means movably mounted on the housingfor actuating the power means, an improved chain oiling apparatuscomprising a casing, inlet means for supplying oil to the casing, outletmeans for supplying oil from the casing to the guide bar, plunger meanswithin the casing and being movable toward the outlet means to force oilfrom the casing through the outlet means, linkage means for moving theplunger within the casing extending from the plunger and having an endportion adjacent the trigger, bell crank means rotatably mounted on thehousing and providing a first lever portion extending from the housingand a second lever portion within the housing, rotation of the firstlever portion causing rotation of the second lever portion, the endportion of the linkage means being connected to the second lever portionfor movement therewith whereby the plunger means may be moved toward theoutlet means of the casing by rotating the first lever portion of thebell crank means, the trigger means being engageable with the endportion of the linkage means when the trigger means is moved to actuatethe power means to move the linkage means so that the plunger is movedtoward the outlet means and oil is forced by the plunger means throughthe outlet means to the guide bar.

2. The apparatus of claim 1 in which the end portion of the linkagemeans extends generally parallel to the axis of rotation of the bellcrank means, the trigger means being rotatable about an axis extendinggenerally parallel to the axis of rotation of the bell crank means andincluding an actuating portion engageable with the end portion of thelinkage means when the trigger means is rotated to actuate the powermeans.

3. In a chain saw having a housing, an elongated guide bar mounted onthe housing and extending therefrom, an endless saw chain trained aroundthe guide bar, power means within the housing for moving the saw chainaround the guide bar, and trigger means movably mounted on the housingfor actuating the power means, an improved chain oiling apparatuscomprising a casing, inlet means for supplying oil to the casing, outletmeans for supplying oil from the casing to the guide bar, plunger meanswithin the casing and being movable toward the outlet means to force oilfrom the casing through the outlet means, linkage means for moving theplunger within the casing extending from the plunger and having an endportion adjacent the trigger, the trigger means being'engageable withthe end portion of the linkage means when the trigger means is moved toactuate the power means to move the linkage means so that the plungermeans is moved toward the outlet means and oil is forced by the plungermeans through the outlet means to the guide bar.

4. The apparatus of claim 3 including linkage-moving means movablymounted on the housing adjacent the end portion of the linkage means,the linkage-moving means being engageable with the linkage means wherebythe linkage means can be moved to move the plunger means toward theoutlet means independently of movement'of the trigger means.

5. The apparatus of claim 3 including a lever rotatably mounted on thehousing adjacent the end portion of the linkage means, rotation of thelever causing movement of the linkage means to move the plunger meanstoward the outlet means independently of movement of the trigger means.

6. An oiling apparatus for a power tool having a movable work part,power means for moving the work part and movable control meansoperatively associated with the power means for varying the speed of thework piece comprising an oil pump having a casing and a plunger movablymounted within the casing, the casing being provided with oil inletmeans and oil outlet means, movement of the plunger toward the oiloutlet means forcing oil from the casing through the outlet means,linkage means extending from the plunger to adjacent the control means,the linkage means being movable by the control means when the controlmeans is moved to increase the speed of the work part to move theplunger toward the oil outlet means and force oil through the oil outletmeans.

7. The apparatus of claim 6 including linkage-moving means mounted onthe power tool adjacent the control means for moving the linkage meansindependently of the control means.

1. In a chain saw having a housing, an elongated guide bar mounted onthe housing and extending therefrom, an endless saw chain trained aroundthe guide bar, power means within the housing for moving the saw chainaround the guide bar, and trigger means movably mounted on the housingfor actuating the power means, an improved chain oiling apparatuscomprising a casing, inlet means for supplying oil to the casing, outletmeans for supplying oil from the casing to the guide bar, plunger meanswithin the casing and being movable toward the outlet means to force oilfrom the casing through the outlet means, linkage means for moving theplunger within the casing extending from the plunger and having an endportion adjacent the trigger, bell crank means rotatably mounted on thehousing and providing a first lever portion extending from the housingand a second lever portion within the housing, rotation of the firstlever portion causing rotation of the second lever portion, the endportion of the linkage means being connected to the second lever portionfor movement therewith whereby the plunger means may be moved toward theoutlet means of the casing by rotating the first lever portion of thebell crank means, the trigger means being engageable with the endportion of the linkage means when the trigger means is moved to actuatethe power means to move the linkage means so that the plunger is movedtoward the outlet means and oil is forced by the plunger means throughthe outlet means to the guide bar.
 2. The apparatus of claim 1 in whIchthe end portion of the linkage means extends generally parallel to theaxis of rotation of the bell crank means, the trigger means beingrotatable about an axis extending generally parallel to the axis ofrotation of the bell crank means and including an actuating portionengageable with the end portion of the linkage means when the triggermeans is rotated to actuate the power means.
 3. In a chain saw having ahousing, an elongated guide bar mounted on the housing and extendingtherefrom, an endless saw chain trained around the guide bar, powermeans within the housing for moving the saw chain around the guide bar,and trigger means movably mounted on the housing for actuating the powermeans, an improved chain oiling apparatus comprising a casing, inletmeans for supplying oil to the casing, outlet means for supplying oilfrom the casing to the guide bar, plunger means within the casing andbeing movable toward the outlet means to force oil from the casingthrough the outlet means, linkage means for moving the plunger withinthe casing extending from the plunger and having an end portion adjacentthe trigger, the trigger means being engageable with the end portion ofthe linkage means when the trigger means is moved to actuate the powermeans to move the linkage means so that the plunger means is movedtoward the outlet means and oil is forced by the plunger means throughthe outlet means to the guide bar.
 4. The apparatus of claim 3 includinglinkage-moving means movably mounted on the housing adjacent the endportion of the linkage means, the linkage-moving means being engageablewith the linkage means whereby the linkage means can be moved to movethe plunger means toward the outlet means independently of movement ofthe trigger means.
 5. The apparatus of claim 3 including a leverrotatably mounted on the housing adjacent the end portion of the linkagemeans, rotation of the lever causing movement of the linkage means tomove the plunger means toward the outlet means independently of movementof the trigger means.
 6. An oiling apparatus for a power tool having amovable work part, power means for moving the work part and movablecontrol means operatively associated with the power means for varyingthe speed of the work piece comprising an oil pump having a casing and aplunger movably mounted within the casing, the casing being providedwith oil inlet means and oil outlet means, movement of the plungertoward the oil outlet means forcing oil from the casing through theoutlet means, linkage means extending from the plunger to adjacent thecontrol means, the linkage means being movable by the control means whenthe control means is moved to increase the speed of the work part tomove the plunger toward the oil outlet means and force oil through theoil outlet means.
 7. The apparatus of claim 6 including linkage-movingmeans mounted on the power tool adjacent the control means for movingthe linkage means independently of the control means.